JPH0724314Y2 - Hydraulic master cylinder mounting structure for bar handle vehicles - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a mounting structure for a hydraulic master cylinder of a bar-handle vehicle that hydraulically actuates a brake or a clutch of a motorcycle or the like.

[Conventional technology]

A hydraulic master cylinder used for brake operation and clutch operation of a bar handle vehicle such as a motorcycle has a cylinder body fixed along a steering bar handle, and an operation lever arranged in front of the bar handle. The base end of is pivotally supported by a support shaft on a lever holder protruding from the cylinder body. The operating lever has an operator whose outer peripheral surface is formed in an arc shape, and the operator is exposed to the tip of the piston protruding from the cylinder hole of the cylinder body. Is pushed into the cylinder hole to reduce the hydraulic chamber at the bottom of the cylinder hole to generate hydraulic pressure (see, for example, Japanese Utility Model Laid-Open No. 61-189997).

Further, in the above-described operation, the piston in the cylinder hole moves linearly in the axial direction of the cylinder body due to the pushing of the operator, whereas the operator of the operating lever moves in the circular arc with the support shaft as the fulcrum. Therefore, as the operating lever approaches the bar handle, the actuator gradually tries to deviate from the axis of the cylinder hole, but the arc-shaped outer peripheral surface of the operator slides on the tip of the piston, By gradually changing the contact area with the piston, the pushing point of the action part with respect to the piston is maintained approximately on the axis of the cylinder body. In proportion to the distance, that is, the piston stroke, as shown by the broken line A in FIG. 4, the hydraulic pressure increases at a constant rate from the initial operation.

[Problems to be solved by the device]

However, in recent braking operations, there is a demand for a braking characteristic in which the hydraulic fluid for the brake is quickly boosted in the early stage of braking and the increase is moderate in the latter half. Such characteristics are also useful from the viewpoint of preventing the occurrence of tire lock in the latter half of braking.

Further, there is a demand for a hydraulic master cylinder capable of engaging the clutch slowly and smoothly even when the clutch is operated.

The present invention has been made against such a background, and its purpose is to determine the relationship between the lever stroke and the piston stroke of the operating lever by changing the hydraulic fluid in the initial stage of the operation when the operation lever is gripped. The hydraulic pressure master cylinder mounting structure for a bar handle vehicle solves the above problem by setting so that the hydraulic fluid gradually rises in the latter half of the subsequent operation.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention has a lever bracket projecting from a steering bar handle toward the front of a vehicle body, and a base end of an operation lever arranged in front of the bar handle is supported by a spindle. It is pivotally supported by a lever bracket, and the tip of a push rod protruding from the cylinder body of the hydraulic master cylinder is pivotally supported by a support pin on either one of the operation lever and the bar handle. On the other hand, the bottom end of the cylinder body is pivotally supported by a support pin, and the support shaft and both support pins are tilted toward the support shaft side as the operation lever is gripped. It is characterized in that it is arranged at a position.

[Action]

According to the above configuration, by gripping the operation lever,
As the operating lever approaches the bar handle, the supporting pin on the operating lever side draws an arcuate locus with the pivot of the operating lever as the fulcrum, and the hydraulic master cylinder uses the supporting pin on the bar handle side as the fulcrum. The operation lever tilts toward the supporting shaft side, and the pushing force of the operating lever accompanying this acts on the piston inside the cylinder body from the supporting pin on the operating lever side via the push rod.

In this way, the hydraulic master cylinder tilts toward the support shaft with the support pin on the bar handle side as the fulcrum. The inclination of the master cylinder toward the support shaft is small, so the piston stroke is approximately proportional to the lever stroke, but the inclination of the hydraulic master cylinder toward the support shaft gradually increases as the operating lever approaches the bar handle. Since it becomes larger, the piston stroke with respect to the lever stroke decreases, and the relationship between the lever stroke and the piston stroke becomes a quadratic curve as shown by the solid line B in FIG.

Therefore, the pushing force of the operating lever with respect to the push rod is increased in the early stage of the operation when the piston stroke is approximately proportional to the lever stroke, and the hydraulic fluid is quickly pressurized.
In the latter half of the operation in which the piston stroke with respect to the lever stroke gradually decreases, the pressure increase of the hydraulic fluid gradually becomes gentle.

〔Example〕

An embodiment in which the present invention is applied to a front brake of a motorcycle will be described below with reference to FIGS. 1 to 4.

On the steering bar handle 1, a lever bracket 3 for mounting a hydraulic master cylinder is provided at a position close to an inner end of the right grip 2 and a base end portion of the lever bracket 3 is attached to the bar handle 1 by a bolt 4.
The bar handle 1 is fixedly attached so as to project from the bar handle 1 toward the front of the vehicle body. A bearing portion 5 is provided on the base end portion of the lever bracket 3 so as to project toward the grip 2 along the front portion of the bar handle 1. At the tip of the lever bracket 3, an operation lever 6 arranged in front of the grip 2 is pivotally supported at its base end by a support shaft 7.

The operating lever 6 has a bearing portion 8 bulgingly formed at a position facing the bearing portion 5 of the lever bracket 3, and the push rod protruding from the cylinder body 10 of the hydraulic master cylinder 9 is provided on the bearing portion 8. The tip end of 13 is pivotally supported by the support pin 15, and the bottom end of the cylinder body 10 is pivotally supported by the bearing pin 5 of the lever bracket 3 by the support pin 16. And the operating lever 6 are installed in the front-rear direction of the vehicle body.

A cylinder hole 11 is provided in the cylinder body 10 so as to open toward the operation lever 6 side, and a reservoir 14 is integrally provided in the upper portion. In the cylinder hole 11, the piston 12 and the proximal end side of the push rod 13 are inserted, and a hydraulic chamber 17 is defined between the piston 12 and the cylinder hole 11, and at the same time, in the hydraulic chamber 17, A brake hose 18 is connected to the front of the bar handle 1 passing through the lever bracket 3.

Further, the support shaft 7 of the operation lever 6 and the support pins 15 and 16 of the hydraulic master cylinder 9 are accompanied by a grip operation of the operation lever 6,
The hydraulic master cylinder 9 is arranged at a position where it is tilted toward the support shaft 7.

That is, in this embodiment, the operation lever 6 when not in operation is the first
The support shaft 15 and the support pin 15 on the operation lever 6 side, which are located at the backward limit shown by the imaginary line in the figures and FIG. The support pin 15 on the operation lever 6 side and the support pin 16 on the bar handle 1 side are in a parallel relationship, and the central axis L2 of the hydraulic master cylinder 9 passing therethrough is orthogonal to the bar handle 1 and the axis L1. It is in.

The support pin 15 on the side of the operation lever 6 moves from the retracted limit position shown in the imaginary line in FIG. 3 when the operation lever 6 is gripped and operated.
It rotates clockwise on a locus R1 with the support shaft 7 as a fulcrum, and as the support pin 15 rotates, the hydraulic master cylinder 9 uses the support pin 16 on the bar handle 1 side as a fulcrum to support the support shaft 7 side. As the operating lever 6 approaches the bar handle 1 and the distance between the support pins 15 and 16 becomes narrower, the push rod 13 is pushed into the cylinder hole 11, and the push rod 13 is further moved to the cylinder. The piston 12 in the hole 11 is pushed toward the bottom to increase the pressure of the hydraulic fluid in the hydraulic chamber 17. The hydraulic fluid whose pressure is increased in the hydraulic chamber 17 is sent to a front brake (not shown) through the brake hose 18 to hydraulically operate the front brake.

In this way, the hydraulic master cylinder 9 is
Since it is set so as to tilt toward the support shaft 7 with the support pin 16 on the side of the fulcrum as the fulcrum, the operation lever 6 is moved from the non-actuated position at the backward limit.
At the beginning of the operation when the grip is started, the hydraulic master cylinder 9
The piston stroke is substantially proportional to the lever stroke because the inclination of the hydraulic actuator toward the support shaft 7 side is small, but as the operating lever 6 approaches the bar handle 1, the hydraulic master cylinder 9 moves toward the support shaft 7 side. Since the inclination gradually increases, the piston stroke with respect to the lever stroke decreases, and the relationship between the lever stroke and the piston stroke becomes a quadratic curve as shown by the solid line B in FIG.

Therefore, the pushing force of the operation lever 6 with respect to the push rod 13 is in the initial stage of the operation in which the piston stroke is substantially proportional to the lever stroke, the hydraulic fluid is quickly increased in pressure, and the piston stroke relative to the lever stroke is gradually reduced. Then, the pressurization of the hydraulic fluid gradually becomes gentle. As described above, according to the present embodiment, when braking is performed, an excessive increase in the braking torque is suppressed in the latter half of the operation, so that it is possible to prevent the occurrence of tire lock.

Further, by changing the support shaft 7 and both support pins 15 and 16 within the scope of the technical concept of the present invention to change the mounting angle of the hydraulic master cylinder 9 with respect to the operating lever 6, different working fluids are obtained. It is possible to obtain various rising characteristics and operation feelings.

FIG. 5 shows another embodiment of the present invention. The overall structure is substantially the same as that of the above embodiment, but the reservoir 14 is separate from the cylinder body 10 and the top bridge 19 located at the center of the vehicle body is shown. It is fixed to.

In both of the above embodiments, the cylinder body is pivotally supported on the bar handle side and the push rod is pivotally supported on the operation lever side, but this may be reversed.

Further, if the present invention is applied to the hydraulic master cylinder for clutch, when the operating lever being held is returned and the clutch is engaged, the movement of the piston in the return direction becomes slow in the first half, so that the clutch engaging operation can be performed. This eases the burden on the driver and also allows the clutch to be loosely connected, so that the durability of the drive parts can be improved.

[Effect of device]

In the present invention, as described above, the lever bracket is projected from the steering bar handle toward the front of the vehicle body, and the base end of the operation lever disposed in front of the bar handle is pivotally supported by the lever bracket on the support shaft. The tip of the push rod protruding from the cylinder body of the hydraulic master cylinder is pivotally supported by a support pin on either one of the operation lever and the bar handle, and at the other of the bar handle and the operation lever. The bottom end of the cylinder body is pivotally supported by a support pin,
In addition, by disposing the support shaft and both support pins at a position where the hydraulic master cylinder tilts toward the support shaft in accordance with the operation of gripping the operation lever, at the initial stage of the operation when the operation lever is started to be gripped. The hydraulic master cylinder has a characteristic that the hydraulic fluid is rapidly increased in pressure and the hydraulic fluid is gradually increased in pressure in the latter half of the operation. In braking operation, excessive increase of the braking torque in the latter half of the operation is suppressed. Therefore, it is possible to prevent the occurrence of tire lock, and in the clutch operation, the first half of the return of the piston becomes gradual, so that the clutch connection is smoothly performed, the burden on the driver is reduced, and the drive parts are Durability is improved.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention, and FIG. 1 is a plan view showing a mounting state of a hydraulic master cylinder.
2 is a sectional view taken along the line II-II in FIG. 1. FIG. 3 is an explanatory view showing an operating state, FIG. 4 is an explanatory view showing a relationship between a lever stroke and a piston stroke, and FIG. 5 is another embodiment of the present invention. It is a top view showing an example. 1 ... Steering bar handle, 3 ... Lever bracket, 6
... Operating lever, 7 ... Support lever 6 spindle, 9 ... Hydraulic master cylinder, 10 ... Cylinder body, 11 ... Cylinder hole, 12
... Piston, 13 ... Push rod, 15 ... Support lever 6 side support pin, 16 ... Bar handle 1 side support pin, L1 ... Axis connecting the support shaft 7 and support pin 15, L2 ... Support pins 15,16 Trajectory of the support pin 15 with the central axis of the hydraulic master cylinder 9 passing through, R1, ...

Claims (1)

[Scope of utility model registration request] 1. A lever bracket (3) is projected from a steering bar handle (1) toward the front of a vehicle body to support a base end of an operation lever (6) arranged in front of the bar handle (1). The shaft (7) is pivotally supported by the lever bracket (3), and one of the operation lever (6) and the bar handle (1) is
The tip of the push rod (13) protruding from the cylinder body (10) of the hydraulic master cylinder (9) supports the support pin (15).
And the bar handle (1) and the operation lever (6), the bottom end of the cylinder body (10) is pivotally supported by a support pin (16), and the support shaft (7). The support pins (15) and (16) are arranged at a position where the hydraulic master cylinder (9) tilts toward the support shaft (7) as the operation lever (6) is gripped. Hydraulic master cylinder mounting structure for bar handle vehicles.